1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2006 Peter Wemm 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 /* 30 * AMD64 machine dependent routines for kvm and minidumps. 31 */ 32 33 #include <sys/param.h> 34 #include <sys/endian.h> 35 #include <stdint.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <unistd.h> 39 #include <vm/vm.h> 40 #include <kvm.h> 41 42 #include "../../sys/amd64/include/minidump.h" 43 44 #include <limits.h> 45 46 #include "kvm_private.h" 47 #include "kvm_amd64.h" 48 49 #define amd64_round_page(x) roundup2((kvaddr_t)(x), AMD64_PAGE_SIZE) 50 #define VM_IS_V1(vm) (vm->hdr.version == 1) 51 #define VA_OFF(vm, va) \ 52 (VM_IS_V1(vm) ? ((va) & (AMD64_PAGE_SIZE - 1)) : ((va) & AMD64_PAGE_MASK)) 53 54 struct vmstate { 55 struct minidumphdr hdr; 56 }; 57 58 static vm_prot_t 59 _amd64_entry_to_prot(uint64_t entry) 60 { 61 vm_prot_t prot = VM_PROT_READ; 62 63 if ((entry & AMD64_PG_RW) != 0) 64 prot |= VM_PROT_WRITE; 65 if ((entry & AMD64_PG_NX) == 0) 66 prot |= VM_PROT_EXECUTE; 67 return prot; 68 } 69 70 /* 71 * Version 2 minidumps use page directory entries, while version 1 use page 72 * table entries. 73 */ 74 75 static amd64_pde_t 76 _amd64_pde_get(kvm_t *kd, u_long pdeindex) 77 { 78 amd64_pde_t *pde = _kvm_pmap_get(kd, pdeindex, sizeof(*pde)); 79 80 return le64toh(*pde); 81 } 82 83 static amd64_pte_t 84 _amd64_pte_get(kvm_t *kd, u_long pteindex) 85 { 86 amd64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte)); 87 88 return le64toh(*pte); 89 } 90 91 /* Get the first page table entry for a given page directory index. */ 92 static amd64_pte_t * 93 _amd64_pde_first_pte(kvm_t *kd, u_long pdeindex) 94 { 95 u_long *pa; 96 97 pa = _kvm_pmap_get(kd, pdeindex, sizeof(amd64_pde_t)); 98 if (pa == NULL) 99 return NULL; 100 return _kvm_map_get(kd, *pa & AMD64_PG_FRAME, AMD64_PAGE_SIZE); 101 } 102 103 static int 104 _amd64_minidump_probe(kvm_t *kd) 105 { 106 107 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) && 108 _kvm_is_minidump(kd)); 109 } 110 111 static void 112 _amd64_minidump_freevtop(kvm_t *kd) 113 { 114 struct vmstate *vm = kd->vmst; 115 116 free(vm); 117 kd->vmst = NULL; 118 } 119 120 static int 121 _amd64_minidump_initvtop(kvm_t *kd) 122 { 123 struct vmstate *vmst; 124 off_t off, dump_avail_off, sparse_off; 125 126 vmst = _kvm_malloc(kd, sizeof(*vmst)); 127 if (vmst == NULL) { 128 _kvm_err(kd, kd->program, "cannot allocate vm"); 129 return (-1); 130 } 131 kd->vmst = vmst; 132 if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) != 133 sizeof(vmst->hdr)) { 134 _kvm_err(kd, kd->program, "cannot read dump header"); 135 return (-1); 136 } 137 if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) { 138 _kvm_err(kd, kd->program, "not a minidump for this platform"); 139 return (-1); 140 } 141 142 /* 143 * NB: amd64 minidump header is binary compatible between version 1 144 * and version 2; version 3 adds the dumpavailsize field 145 */ 146 vmst->hdr.version = le32toh(vmst->hdr.version); 147 if (vmst->hdr.version > MINIDUMP_VERSION || vmst->hdr.version < 1) { 148 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d", 149 MINIDUMP_VERSION, vmst->hdr.version); 150 return (-1); 151 } 152 vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize); 153 vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize); 154 vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize); 155 vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase); 156 vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase); 157 vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend); 158 vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ? 159 le32toh(vmst->hdr.dumpavailsize) : 0; 160 161 /* Skip header and msgbuf */ 162 dump_avail_off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize); 163 164 /* Skip dump_avail */ 165 off = dump_avail_off + amd64_round_page(vmst->hdr.dumpavailsize); 166 167 sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) + 168 amd64_round_page(vmst->hdr.pmapsize); 169 if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off, 170 vmst->hdr.bitmapsize, off, sparse_off, AMD64_PAGE_SIZE) == -1) { 171 return (-1); 172 } 173 off += amd64_round_page(vmst->hdr.bitmapsize); 174 175 if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) { 176 return (-1); 177 } 178 off += amd64_round_page(vmst->hdr.pmapsize); 179 180 return (0); 181 } 182 183 static int 184 _amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa) 185 { 186 struct vmstate *vm; 187 amd64_physaddr_t offset; 188 amd64_pte_t pte; 189 kvaddr_t pteindex; 190 amd64_physaddr_t a; 191 off_t ofs; 192 193 vm = kd->vmst; 194 offset = va & AMD64_PAGE_MASK; 195 196 if (va >= vm->hdr.kernbase) { 197 pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT; 198 if (pteindex >= vm->hdr.pmapsize / sizeof(pte)) 199 goto invalid; 200 pte = _amd64_pte_get(kd, pteindex); 201 if ((pte & AMD64_PG_V) == 0) { 202 _kvm_err(kd, kd->program, 203 "_amd64_minidump_vatop_v1: pte not valid"); 204 goto invalid; 205 } 206 a = pte & AMD64_PG_FRAME; 207 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 208 if (ofs == -1) { 209 _kvm_err(kd, kd->program, 210 "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump", 211 (uintmax_t)a); 212 goto invalid; 213 } 214 *pa = ofs + offset; 215 return (AMD64_PAGE_SIZE - offset); 216 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 217 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 218 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 219 if (ofs == -1) { 220 _kvm_err(kd, kd->program, 221 "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump", 222 (uintmax_t)va); 223 goto invalid; 224 } 225 *pa = ofs + offset; 226 return (AMD64_PAGE_SIZE - offset); 227 } else { 228 _kvm_err(kd, kd->program, 229 "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped", 230 (uintmax_t)va); 231 goto invalid; 232 } 233 234 invalid: 235 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 236 return (0); 237 } 238 239 static int 240 _amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 241 { 242 amd64_pte_t pt[AMD64_NPTEPG]; 243 struct vmstate *vm; 244 amd64_physaddr_t offset; 245 amd64_pde_t pde; 246 amd64_pte_t pte; 247 kvaddr_t pteindex; 248 kvaddr_t pdeindex; 249 amd64_physaddr_t a; 250 off_t ofs; 251 252 vm = kd->vmst; 253 offset = va & AMD64_PAGE_MASK; 254 255 if (va >= vm->hdr.kernbase) { 256 pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT; 257 if (pdeindex >= vm->hdr.pmapsize / sizeof(pde)) 258 goto invalid; 259 pde = _amd64_pde_get(kd, pdeindex); 260 if ((pde & AMD64_PG_V) == 0) { 261 _kvm_err(kd, kd->program, 262 "_amd64_minidump_vatop: pde not valid"); 263 goto invalid; 264 } 265 if ((pde & AMD64_PG_PS) == 0) { 266 a = pde & AMD64_PG_FRAME; 267 /* TODO: Just read the single PTE */ 268 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 269 if (ofs == -1) { 270 _kvm_err(kd, kd->program, 271 "cannot find page table entry for %ju", 272 (uintmax_t)a); 273 goto invalid; 274 } 275 if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) != 276 AMD64_PAGE_SIZE) { 277 _kvm_err(kd, kd->program, 278 "cannot read page table entry for %ju", 279 (uintmax_t)a); 280 goto invalid; 281 } 282 pteindex = (va >> AMD64_PAGE_SHIFT) & 283 (AMD64_NPTEPG - 1); 284 pte = le64toh(pt[pteindex]); 285 if ((pte & AMD64_PG_V) == 0) { 286 _kvm_err(kd, kd->program, 287 "_amd64_minidump_vatop: pte not valid"); 288 goto invalid; 289 } 290 a = pte & AMD64_PG_FRAME; 291 } else { 292 a = pde & AMD64_PG_PS_FRAME; 293 a += (va & AMD64_PDRMASK) ^ offset; 294 } 295 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 296 if (ofs == -1) { 297 _kvm_err(kd, kd->program, 298 "_amd64_minidump_vatop: physical address 0x%jx not in minidump", 299 (uintmax_t)a); 300 goto invalid; 301 } 302 *pa = ofs + offset; 303 return (AMD64_PAGE_SIZE - offset); 304 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 305 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 306 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 307 if (ofs == -1) { 308 _kvm_err(kd, kd->program, 309 "_amd64_minidump_vatop: direct map address 0x%jx not in minidump", 310 (uintmax_t)va); 311 goto invalid; 312 } 313 *pa = ofs + offset; 314 return (AMD64_PAGE_SIZE - offset); 315 } else { 316 _kvm_err(kd, kd->program, 317 "_amd64_minidump_vatop: virtual address 0x%jx not minidumped", 318 (uintmax_t)va); 319 goto invalid; 320 } 321 322 invalid: 323 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 324 return (0); 325 } 326 327 static int 328 _amd64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 329 { 330 331 if (ISALIVE(kd)) { 332 _kvm_err(kd, 0, 333 "_amd64_minidump_kvatop called in live kernel!"); 334 return (0); 335 } 336 if (((struct vmstate *)kd->vmst)->hdr.version == 1) 337 return (_amd64_minidump_vatop_v1(kd, va, pa)); 338 else 339 return (_amd64_minidump_vatop(kd, va, pa)); 340 } 341 342 static int 343 _amd64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg) 344 { 345 struct vmstate *vm = kd->vmst; 346 u_long npdes = vm->hdr.pmapsize / sizeof(amd64_pde_t); 347 u_long bmindex, dva, pa, pdeindex, va; 348 struct kvm_bitmap bm; 349 int ret = 0; 350 vm_prot_t prot; 351 unsigned int pgsz = AMD64_PAGE_SIZE; 352 353 if (vm->hdr.version < 2) 354 return (0); 355 356 if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex)) 357 return (0); 358 359 for (pdeindex = 0; pdeindex < npdes; pdeindex++) { 360 amd64_pde_t pde = _amd64_pde_get(kd, pdeindex); 361 amd64_pte_t *ptes; 362 u_long i; 363 364 va = vm->hdr.kernbase + (pdeindex << AMD64_PDRSHIFT); 365 if ((pde & AMD64_PG_V) == 0) 366 continue; 367 368 if ((pde & AMD64_PG_PS) != 0) { 369 /* 370 * Large page. Iterate on each 4K page section 371 * within this page. This differs from 4K pages in 372 * that every page here uses the same PDE to 373 * generate permissions. 374 */ 375 pa = (pde & AMD64_PG_PS_FRAME) + 376 ((va & AMD64_PDRMASK) ^ VA_OFF(vm, va)); 377 dva = vm->hdr.dmapbase + pa; 378 _kvm_bitmap_set(&bm, _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE)); 379 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 380 _amd64_entry_to_prot(pde), AMD64_NBPDR, pgsz)) { 381 goto out; 382 } 383 continue; 384 } 385 386 /* 4K pages: pde references another page of entries. */ 387 ptes = _amd64_pde_first_pte(kd, pdeindex); 388 /* Ignore page directory pages that were not dumped. */ 389 if (ptes == NULL) 390 continue; 391 392 for (i = 0; i < AMD64_NPTEPG; i++) { 393 amd64_pte_t pte = (u_long)ptes[i]; 394 395 pa = pte & AMD64_PG_FRAME; 396 dva = vm->hdr.dmapbase + pa; 397 if ((pte & AMD64_PG_V) != 0) { 398 _kvm_bitmap_set(&bm, 399 _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE)); 400 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 401 _amd64_entry_to_prot(pte), pgsz, 0)) { 402 goto out; 403 } 404 } 405 va += AMD64_PAGE_SIZE; 406 } 407 } 408 409 while (_kvm_bitmap_next(&bm, &bmindex)) { 410 pa = _kvm_bit_id_pa(kd, bmindex, AMD64_PAGE_SIZE); 411 if (pa == _KVM_PA_INVALID) 412 break; 413 dva = vm->hdr.dmapbase + pa; 414 if (vm->hdr.dmapend < (dva + pgsz)) 415 break; 416 va = 0; 417 /* amd64/pmap.c: create_pagetables(): dmap always R|W. */ 418 prot = VM_PROT_READ | VM_PROT_WRITE; 419 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, prot, pgsz, 0)) { 420 goto out; 421 } 422 } 423 424 ret = 1; 425 426 out: 427 _kvm_bitmap_deinit(&bm); 428 return (ret); 429 } 430 431 static struct kvm_arch kvm_amd64_minidump = { 432 .ka_probe = _amd64_minidump_probe, 433 .ka_initvtop = _amd64_minidump_initvtop, 434 .ka_freevtop = _amd64_minidump_freevtop, 435 .ka_kvatop = _amd64_minidump_kvatop, 436 .ka_native = _amd64_native, 437 .ka_walk_pages = _amd64_minidump_walk_pages, 438 }; 439 440 KVM_ARCH(kvm_amd64_minidump); 441